0000000000248187
AUTHOR
Péter Kovács
Induction of digoxin-like material production, and the digoxin binding in the unicellular organism Tetrahymena by digitoxin.
Thin layer chromatographic, and laser-confocal microscopic analyses with a monoclonal antibody to digoxin also displaying high affinity to digoxigenin, were used to determine the presence and localization of cardioactive glycosides. Tetrahymena pyriformis was found to possess digitoxigenin-like material, but digoxin, digitoxin, digoxigenin, gitoxin and lanatoside C were not detected. Digitoxin treatment elicited the appearance of a digoxin-like material in the progeny generations. Digoxin was taken up by untreated Tetrahymena, especially strongly 24 h after digitoxin treatment. While the cardenolide was localized in vesicles of the cell body in untreated Tetrahymena, the engulfed digoxin ap…
IDENTIFICATION OF LECTINS IN THE KINETIDS OFTETRAHYMENA PYRIFORMIS
Previously we described lectin-like molecules in the ciliate Tetrahymena pyriformis; by application of synthetic neoglycoconjugates it is now shown that T. pyriformis contains considerable amounts of both a beta-D-glucose- and a lactose-specific lectin. No evidence for the presence of alpha-D-mannose-, alpha-D-galactose- or of alpha-L-fucose-specific lectins could be obtained. The two lectins, identified in T. pyriformis, are associated with the kinetids. During cell division the lectins disappear or become masked in the fission furrow. Therefore, we assume that these lectins are involved in the organization of the distribution pattern of the kinetids during cell division perhaps due to lec…
Polymorphism in the immunoglobulin-like domains of the receptor tyrosine kinase from the sponge Geodia cydonium.
Sponges [Porifera] are the phylogenetically oldest phylum of the Metazoa. They are provided with both cellular and humoral allorecognition systems. The underlying molecules are not yet known. To study allorecognition in sponges we first determined the frequency of graft rejection in a natural population of the marine sponge Geodia cydonium. We then determined, for the first time at the molecular level, the degree of sequence polymorphism in segments of one molecule which may be related to sponge allorecognition and host defense: the Ig-like domains from the receptor tyrosine kinase [RTK]. Thirty six pairs of auto- and allografts were assayed, either by parabiotic attachment or insertion of …